Cephalic index

“ In this way a great deal of valuable material for study has been accumulated, but much work remains to be done in this direction.
Methods of Dealing with Anthropometric Data. Not only have head, body, and limb measurements 46been recorded, but the device of an “index” has been adopted which gives the ratio between two measurements, as, for example, in the previously-mentioned cephalic index (p. 34) . The averages or means of series of indices obtained from one people have been compared with those obtained from other peoples ”

“ This ratio (of 75%) is termed the cephalic or breadth-index, which in such an instance would be described as equal to 75. A skull providing a breadth-index of 75 will naturally possess very different proportions from another which provides a corresponding index equal to 85. And in fact this particular index in human skulls varies from about 58 to 90 in undistorted examples (fig. 4) . Such is the general scheme of Retzius’s system of classification of skulls by means of indices, and one of his earliest applications of the method was to the inhabitants of Sweden. ”

“ The cephalic indices show 5 men and 4 women to be dolichocephalic, 3 men and 6 women brachycephalic; the median for the men is 76.9, for the women 79.4. One man is platycephalic, 3 men and 1 woman mesocephalic and the rest hypsicephalic as regards length-height, all are hypsicephalic as regards breadth-height, in each respect the women being markedly more hypsicephalic than the men. The shape is noted as oval in 1 man and 9 women, round oval in 1 of each sex, ellipsoidal in 1 man and pyriform in 4 men. ”

“ Cephalic version can be so seldom performed however, and is so difficult, and sometimes dangerous, that it is seldom or never attempted; more particularly as pelvic version can always be substituted, and is more easy and safe. ”

“ In reference to the structure of the head-capsule in the imago, it appears that the clypeus and labrum represent, as already said, an unpaired median outgrowth of the oral piece. According to W. A. Riley (1904) the epicranium or “vertex,” the compound eyes and the front divisions of the genae are formed by the cephalic lobes of the embryo (belonging to the ocular segment) , while the mandibular and maxillary segments form the hinder parts of the genae and the hypopharynx. ”

“ CEPHALIC, generally signifies whatever relates to the head. Hence these remedies that are given for disorders of that part, are denominated cephalic medicines. Under this description are comprehended cordials, and whatever tends to promote a free circulation of the blood through the brain: thus cephalic snuff is taken with a view to remove pains in the head, by occasioning the patient to sneeze, and, in this manner, perhaps, giving vent to obstructions in the smaller vessels. Such is the imperfect theory of cephalic medicines ”

“ The dolichocephalic crania are, as a rule, distinctly akrocephalic, that is, the length-height index is superior to the length-breadth index, but this is not the case with the brachycephals. I find the average length-height index in the living subject of a dozen inland tribes is 72.5 for 131 males and 78.2 for 40 females. That is, so far as our measurements go, the women are more akrocephalic than the men, which is unusual. ”

“ The body cavity is continued into the region of the head; and the mesoblast lining the cephalic section of the body cavity is divided into the same number of head cavities as in Elasmobranchii, viz. one in front of the mouth, and one in the mandibular and one in each of the following arches.
Fig. 75. Transverse section through the cephalic region of a young Newt embryo. (After Scott and Osborn.)
In.hy. invaginated hypoblast, the dorsal part of which will form the notochord; ep. epiblast of neural plate; sp. splanchnopleure; al. alimentary tract; yk. and Y.hy. yolk-cells. ”

“ At the end of the fifth month, the weight of the fetus is from nine to ten ounces; whereas an average infant when born at the expiration of the full term of pregnancy, that is, with the completion of the tenth month, weighs about seven pounds. The fetus, therefore, acquires roundly ninety per cent, of its weight during the second half of pregnancy, which clearly indicates that Nature reserves this period of gestation for the fetus to increase in size, a phenomenon less mysterious but no less important than the evolution of the embryo. ”

“ Whenever the child can be brought away by the natural passages, though it be piecemeal, it always is so brought, unless the danger to the mother be greater than by the cesarian operation, in which case that operation is resorted to. By means of an instrument called the Cephalotribe, which crushes the head, the child may be brought away, unless very large, when the pelvis only measures two inches. When the passage is less than two inches, the only resort is to the cesarean operation, which sometimes succeeds, and saves both mother and child, though more frequently the mother sinks. ”

“ There are very many varieties of deformed pelves, but the same rules apply to them as to those already mentioned, except that the caesarean section is oftener indicated. Difficulty also not seldom occurs in women with normal pelves from an excessive size in the child through prolonged pregnancy, bigness of one or both parents, or the advanced age or multiparity of the mother. The child's head alone may be of excessive size. Some monsters offer difficulty in delivery from size or shape, but, of course, they are human beings, and are to be considered as such in delivery. ”

“ If the head be on the mother's right side it is called the right cephalo iliac position, and if it be on the left side it is denominated the left cephalo iliac position. The mechanism of spontaneous delivery is the same in them both, and in all their varieties, and so is the mode of rendering assistance, so that a description of one will suffice.
Sometimes, when the labor has lasted long without assistance, one arm will be forced down first, and even appear externally. This used to be considered a separate presentation, and described as such, under the name of presentation of the hand and arm. ”

“ By the end of the third month, or twelfth week, centres of ossification have appeared in most of the bones, the fingers and toes are separated and bear nails in the form of fine membranes; the umbilical cord has definite form, has increased in length and begun to twist. The neck is longer, teeth are forming and the eyes have lids. The amnion and chorion are now in contact, and the villi have disappeared excepting at one point where a small, but complete placenta has developed. The embryo is about 9 centimetres long and weighs about 30 grams. ”

“ Even minor mineral fetal deficiencies degrade the bone structure: the fetus knows it needs nutritional reserves more than it needs to have a full-sized jaw bone or a wide pelvic girdle, and when deprived of maximum fetal nourishment, these non-vital bones become somewhat smaller. Permanently. If mineral deficiencies continue into infancy and childhood, these same bones continue to be shortchanged, and the child ends up with a very narrow face, a jaw bone far too small to hold all the teeth, and in women, a small oven that may have trouble baking babies. ”

“ A pair of cœlomic cavities appears in every segment except the segments of the 2nd, 3rd, and 4th appendages, in which cœlomic cavities do not appear at all. At least eleven pairs of these cavities are produced. The eleventh pair belongs to the seventh abdominal segment.
The first pair of cœlomic cavities is common to the cephalic lobe and the segment of the first appendage (i.e. the cheliceræ) .
The second cœlomic cavity belongs to the segment of the fifth appendage. It is well developed. ”

“ If the head passes through the inlet safely, the rest of the delivery will usually be accomplished with comparative safety. But a marked disproportion between the diameters of the head and pelvis, or limited mouldability of the head, constitutes a serious complication, which will be discussed later in connection with obstetrical operations.
A baby’s head is larger, in proportion to its body, than an adult’s, while the face forms a relatively smaller part of the baby’s than of the adult’s head. ”

“ For this reason, meconium stained fluid escaping during labor in a head presentation may be taken as an evidence of imminent asphyxiation, due to an interruption of the umbilical circulation.
The head is the most important part of the fetus, from an 89obstetrical standpoint, since the process of labor is virtually a series of adaptations of the size, shape and position of the fetal skull to the size and shape of the maternal pelvis. And since the pelvis is rigid and inflexible the adjustment must all be made by the fetal head, which is mouldable because of being incompletely ossified at birth. ”

“ The natural size of the unimpregnated womb is three by one and three-quarter inches, and its weight is one to two ounces. The average size of the pregnant womb just previous to labor is twenty by fourteen inches, and its weight about sixteen ounces. We have, therefore, an increase of about 600% to be got rid of before it assumes again its normal condition. This decrease cannot be accomplished quickly by any known medical miracle. Nature takes time and she will not be hurried: she will do it in an orderly, perfect manner if she is allowed to. ”

“ In France, legitimacy is allowed to children born on the 299th day of pregnancy.
Labor is distinguished by a softening of the soft parts of the female organs of generation, an abundant secretion [148] of mucus, a relaxation of the mouth of the womb, and a forcible contraction of its body. The expulsion of the child is effected by pains of a straining nature. After the birth of the child, the womb contracts to its normal or unimpregnated size, giving forth a discharge, called the lochia, that lasts for several days, and the breasts immediately furnish the secretion of milk. ”

“ ENDOCRINE ANALYSIS The modes of classification glimpsed at are certainly exceedingly broad and sweeping. It is well enough to establish types and classes. But beneath them are sheltered the infinite possibilities of permutations and combinations, which explain the countless variety and complexity of form and function. Every individual born among the vertebrates, for example, must have a certain definite amount and percentage of pituitary gland, anterior and posterior, pineal, thyroid, parathyroid, thymus, adrenal, pancreas, interstitial and so on. ”

“ The placenta is, for the most part, a highly developed portion of the chorionic membrane, which became specialized simply because it happened to receive the best supply of blood. At the time of birth the placenta measures nearly an inch in thickness, is as large around as a breakfast-plate, and generally weighs a pound and a quarter, that is, approximately one-sixth of the weight of the child. ”

“ The long diameter of the head must first conform to one of the long diameters of the inlet, usually oblique, and then turn so that the length of the head is lying antero-posterior in conformity to the long diameter of the outlet through which it next passes. As the head descends and rotates it also describes an arc because the posterior wall of the pelvis, consisting of the sacrum and coccyx, is about three times as deep as the anterior 239wall formed by the symphysis. ”

“ More kinds of radionuclides were found than in the living babies, although the large counting time may have affected the results.
The same counting techniques were used with placental tissues from mothers of three of the stillborns. The placenta is the organ that nourishes an unborn child and through which substances from the mother’s bloodstream are exchanged with those in the baby’s blood. The graphs in Figure 17 show data from this experiment and illustrate the method of interpreting whole body counter data. ”

“ This arc is the future dorsal portion of the embryo, which lags in its development immensely behind the ventral portion.
There is a very distinctly bilobed procephalic region (pr.l) well separated from the segment with the cheliceræ (ch) . It is marked by a shallow groove opening behind into a circular depression (st.) —the earliest rudiment of the stomodæum. The six segments behind the procephalic lobes are the six largest, and each of them bears two prominent appendages. They constitute the six appendage-bearing segments of the adult. ”

“ Scale of Proportionate Measures.
That this scale will be useful we have no doubt, and by working from it much better results can be obtained than by any divisions of the breast measure, for it is based on what has long been an acknowledged fact, that at birth the head is nearly one-fourth the total height of the body, whilst at 7 or 8 it bears the relation of one-seventh, and at 16 it bears the same relative propotions as in the adult, which is differently computed at from 1 to 71⁄2 to 1 to 8. ”

“ A baby weighing less than 2500 grams or about 51⁄2 pounds should be regarded, and treated, as premature, unless it is more than 45 centimetres, or about 18 inches long. This length would indicate greater maturity, and therefore greater viability than would be expected from the weight. A baby weighing less than 1500 grams (3 pounds and 5 ounces) can scarcely be expected to live. ”

“ In general there is no particular difficulty from this position, but on the contrary it is thought by some to be rather favorable than otherwise. The longest diameter of the fœtal pelvis, and shoulders, are adapted to the longest diameter of the mother's pelvis, at the upper strait, and easily pass it. They will also generally pass the external opening in the same direction, unless it be very unyielding, [197] or the child very large; and if they pass the head usually follows, because the parts have been so much dilated by the passage of the body that they offer but little resistance. ”